Communication demands, and particularly wireless communication demands, continue to increase. Next generation wireless communication systems, commonly referred to as “5G communication systems” are being developed, to meet these demands. One important technology to be adopted by 5G communication systems involves the use of base stations which have a large number of input and outputs (sometimes referred to as a massive MIMO system) to serve a large number of communication users. Massive MIMO uses a large excess of antennas and time division duplex operation to serve multiple active user terminals at the same time. Extra antennas focus energy into ever-smaller regions of space to bring huge improvements in throughput and radiated energy efficiency. Such massive MIMO systems may have hundreds of transmit (Tx) and receive (Rx) channels and corresponding RF antennas.
In general communication systems and devices, like other electronics, require testing and, in some cases, calibration. However, testing and calibration can present challenges in the case of a multi-user massive MIMO communication system or terminal which includes a large number of input and outputs. For example, the system performance evaluation depends on the wireless channel characteristics which can be different for different users and different inputs and outputs at the same time. So proper solutions for testing multi-user massive MIMO performance are needed.
Thus it would be desirable to provide a more convenient and more reliable method and system to test and calibrate the performance of a multi-user, multi-input/multi-output communication system or device.